There is no single organism that is "in" alcohol. Alcohol, specifically ethanol, is a chemical compound produced through the process of fermentation.

Fermentation is a biological process where microorganisms, primarily yeasts, break down sugars in the presence of no oxygen. These yeasts consume the sugars and release ethanol and carbon dioxide as byproducts.

So, while yeasts are the primary organisms involved in alcohol production, they are not "in" the alcohol itself. The alcohol is a product of their metabolic activity.